Yesterday I attempted to make the magickal ink for my Register of Service, which I may describe in another thread.

Here is what I did.

Combine:

2 Cups Filtered Water
1/4 Cup Black Walnut Hull Powder
1 Tbsp. Lavender
1 Tbsp. Patchoulli
1 Tbsp. Mugwort
1 Tbsp. Mullein
1 Tbsp. Eucalyptus

Simmer, covered, for two hours, and let steep for eight hours.
https://i.imgur.com/5cVD5EE.jpg

After steeping for about 8 hours, I was left with a mush of plant matter which had mostly absorbed the liquid.
https://i.imgur.com/G72lqUg.jpg

I began by putting the mess in a strainer over a clean pot, and picking up and pressing bits of the plant material with my fingers to squeeze out all the liquid. This left a small amount of viscous black liquid filled with silt, to which I added purified water until it was brought back to one cup worth.
https://i.imgur.com/9hCRK0X.jpg

I prepared a small strainer over a clean measuring cup, and tried to filter the ink through a coffee filter. However, it got clogged almost straight away. Heating the liquid helped little. What I ended up doing was filtering a little liquid at a time, and then replacing the coffee filter, which each time had much of the silt stuck to it. I went through several filters this way.
https://i.imgur.com/KYxSsi5.jpg

At last when about half of the liquid was filtered and the rest of the slush was just too viscous, I pinched the filter into a pouch around the liquid and squeezed gently to help it pass through. I wrung out the filter pouch, leaving the rest of the silt stuck inside, and discarded.
https://i.imgur.com/j3TRfGo.jpg

The dark brown, very reflective liquid I was left with would probably be decent for scrying.
https://i.imgur.com/v7nJwLI.jpg

At this point I mixed in half a teaspoon of PhytoCide Aspen Bark Extract as a preservative. This was a mistake. The data sheet for the bark extract claims that it is only stable up to 75 degrees fahrenheit, so past this point, I could no longer use the stove to evaporate the liquid further if need be. i should have first tested the viscosity of the ink inside the pen, and then added the bark extract very last when I was satisfied with its properties.
https://i.imgur.com/8laa5cL.jpg

Next I began mixing in teaspoons, and then tablespoons of gum arabic to increase the viscosity, testing in the pen periodically. However, though the viscosity increased, the liquid did not take on the flow properties of my reference ink, and continued to flow poorly in comparison. I settled on 8 Tbsp. of gum arabic to my 1 Cup of liquid ink. I had naively thought that viscosity would be a linear property of the liquid which I could scale up or down with the gum arabic, but it turns out that viscosity is more nuanced than that. Next time I will try evaporating first before adding gum arabic, and see how this affects the viscosity in comparison.
https://i.imgur.com/f6Lucxi.jpg

I did not add a few drops of my blood in the end, partly because I was not ready to use the ink in a magickal project yet, and partly because I pussed out about drawing blood with a knife after I failed to do it with a sterilized needle. When the time comes I will either get stupid drunk or buy some diabetic lancets. Here is a photo of my finished ink -- virtually a lifetime supply if it were perfect. I will try a new batch at a later date and post results.
https://i.imgur.com/7rqS20P.jpg

The final product was not ideal in color or viscosity, but was ultimately usable, and a good starting point for further refinement of the process.
https://i.imgur.com/tHUFURA.jpg

Edit: Having forgotten earlier, I added half a teaspoon of Balsamic Vinegar of Modena, since it turns out I didn't have any White Distilled Vinegar.

Also, it turns out that what the ink needed was a couple teaspoons more water. After testing with smaller amounts of ink, I added two teaspoons to my main jar of ink, and it flows much better now. However, its flow properties are still not ideal. I plan next to test the effect on viscosity of adding Vegetable Glycerine.